Apparatus for manufacturing inner tubes



March 1941- R. PATRICK APPARATUS FOR MANUFACTURING INNER TUBES 2Sheets-Sheet 1 Filed Sept. 10, 1936 HVVENTQRw Mardl 1941- R. PATRICKAPPARATUS FOR MANUFACTURING INNER TUBES 2 Sheets-Sheet 2 IN V EN TORROS-5 PATH) BY w @k A T TORNE).

' Patented Mar. 4, i941 UNITED STATES PATENT OFFICE Rosa Patrick,Indianapolis, Ind., assignor, by mesne assignments, to United StatesRubber Company, New York, N. Y., a corporation of New Jersey ApplicationSeptember 10, 1936, Serial No. 100,136

1 Claim.

This invention relates to the manufacture of inner tubes, and inparticular it relates to a method and means for providing an aperture inan inner tube in alignment with a valve stem.

. The adoption of the rubber type of valve stem requires new anddifierent means of treating inner tubes, particularly in respect to theassemblyor rubber valve stems. Rubber valve stems have a flexible rubberbase which is vulcanized directly to the inner tube. Previously it hasbeen customary to assemble the valve stem with the inner tube after theinner tube is in an advanced state of processing.

when an inner tube is extruded from a tubing machine it is customary toinject a lubricating material, such as soapstone powder, into theinterior of the tube. This prevents the walls of the tube from adheringtogether. It is also customary to coat the outer surface of the innertube with a soapstone powder.

In the application of a rubber valve stem to an inner tube it is highlydesirable that the adjoining surfaces of the tube and the valve stembase be free from the presence of lubricating material. It has beengeneral practice to lay a thin sheet of material on top 01 the innertube at a location where the valve stem is to be subsequently applied.This sheet of material is placed on the tube before its exterior wallsare lubricated with a soapstone powder. Directly before the valve stemis applied to the tube the thin sheet of protective material is removedfrom the tube, a hole punched in the tube, and the valve stem applied tothe tube in alignment with the punched hole, This operation isobjectionable in that, when the hole is punched through the wall of thetube it frequently occurs that a small quantity of the lubricatingmaterial issues from the interior of the tube and settles on the outerwall of the tube surrounding the punched hole. As a result of thepresence of such lubricating material, proper adhesion of the tube andvalve stem through vulcanization cannot be obtained, and leakage takesplace while the tube is in operation.

Another object is to assemble the valve stem with the inner tube priorto the dusting of the exterior tube walls with a lubricating material.

A further object is to dispose of the material which is removed to formthe valve stem hole in the tube.

A still further object is to expedite the manutacture oi inner tubes andto obtain economy thereby.

These and other objects and advantages appear more fully in thefollowing detailed description, when considered in connection with theaccompanying drawings, in which;

.Fig. 1 is a side view, partly in section, of a portion of an embodimentof my invention;

Fig. 2 is an end view, in section, taken along section line H-II of Fig.1;

Fig. 3 is a detailed view, in. section, of means for guiding a valvestem into relative position with a cutting means;

Fig. 4 is a side elevational view or a complete embodiment of theinvention;

Fig. 5 is an end elevational view, partly in section, the section beingtaken along section'line V-V of Fig. 1; and

Fig. 6 is a side elevational view, partly in section of a portion of theembodiment of the invention, illustrating a method oi inspection.

Referring to the drawings, and in particular to Figs 1, 2, and 4, Iillustrate an embent of my invention comprising a pedestal l forsupporting a bracket 2 and an arm 3. At the upper part oi the arm 3, andnear the extremity thereof is a recess E into which a plate 5 ispositioned with its top surface normally on an even plane with the topof the arm 3 so as to keep the inner tube from engaging a cutting toolas the tube is mounted and withdrawn. The plate 5 is sup=- ported bypins 6 attached thereto and slidable in apertures within the body of thearm 8. A spring 3 normally maintains this plate 5 in its proper positionrelative to the arm 3.

A cutter tool 8 in tubular form is disposed be= low the top or the plateand is secured to the arm 3. A heating element 98 circumscribes thecutter tool a and functions to elevate the temperature of the cuttertool, thereby assisting in the cutting operation. An aperture llextending through the plate 5 permits the plate to be moved in a mannerallowing the cutting tool 9 to extend therethrough.

The cutting tool 8 is provided with a tapered aperture ii forfacilitating the removal of the material cut from an inner tube. Theaperture l2 connects with a pipe line l8 extending to a r "so with thetank It and communicates with a source of reduced pressure. The bottomof the'tank ll has a removable base It through which accumulations ofcut rubber plugs within the tank it may be removed. Pipe line l3includes a valve ll which is actuated during the operation of theapparatus.

In Fig. 2 an inner tube l8 and a valve stem i9" e through the wall ofthe tube i8, the material re- 7 maining therefrom being in the form of aplug or disc 285. This plug as is removed due to the reduced airpressure within thetubular cutter d. Thereafter the plug is carriedthrough the pipe line and deposited within the tank id.

In order to locate the valve stem is and to force the stem downwardtoward the cutter tool, I provide a tubular guide member 2! adapted forvertical reciprocating movement. The tubular member 20 is slideblysupported within a bushing 22 held by an 28 extending irom the bracket2.

As shown in Fig. 3, a portion oi the tubular member 22 is provided withrock teeth 26 for complementary association with a gear 25. A shait 2tkeyed to the gear'fib also carries an arm 27 to which a connecting link28 is pivotally seposite end connectswith a lever 38 for operating thevalve ii. The-branch connectinglink 3i attaches to the lever 33 througha'slot 34' at the upper part of the connecting link 3!. The purpose ofthe slot 34 is to permit a variation be tween the operation of the valvei I and the vertical movement of the tubular member 2 i This variationis desirable in that vacuum is applied after the tubular member beginsits downward movement, and the vacuum is continued until the tubularmember 2| approaches the limit of its upward movement.

An electric light 35 positioned near the extremity of the arm 3 lles-inthe path of the tube i8 as it is removed from the arm I, thus enabling'7 an operator to inspect the tube as it is withdrawn from the to insurethat the plug a ,hasbeen properly removed from the tube. This I method0! inspection is illustrated in Fig. 6. In the operation oi.theapparatus, an operator places the end of a tube carrying avalv'e'stem c 1 over the arm 8. It is to be understood that thisoperation take place during the manufacture o the-inner tube, and priorto the. splicing of the ends of the tube'to form a tubular annulus. The

end of the valve stem i9 is manually guided into z the aperture of thetubular member 2!.

Thereafter the operator presses the foot pedal 29, thus actuating thegear and moving the tubular member 2! downward. The tubular member 2|engages with the base of the valve stem i9 and i forces same downward todepress the spring 3. As a result of this movement,the plate 5 is moveddownward, and the cutting tool 9 extends through the plate to distanceequal to at least the thickness of the inner tube wall.

The heating element it is in continuous operation, and therefore theknife edge of the cutting tool 5,

by the elevated temperature, easily cuts a circular aperture through thewall ofthetubei8.

Simultaneously with the downward movement of thetubular member 2!, thevalve i1 is actuated, resulting in a reduced pressure at the under sideof the plug 26. As soon as the wall of the tube It is completelysevered, the plug 29 is carried by the moving air through tion It andinto the tank ll.

When'the operator releases the pedal 29 the spring 30 returns themechanism to its normal the pipe connecposition and the valve i! isclosed. Thereatterssthe operator slides the tube oi! the arm 3; and asit passes the electric light theoperators line of vision extends throughthe aperture of the .valve stem, and it is readily ascertained ii theplug 20 is entirely removed from the wall 01 40 the inner tube. I eWhile I have shown certain preferred embodimerits of myinvention, itwill be understood that modifications may be made therein withoutdeparting from the spirit of the invention and the scope of the appendedclaim;

Having thus described my invention, what I claim and desire to protectby Letters Patent is:

Apparatus for manipulating inner tubes comprising a support insertableinto an open end of

